U.S. patent number 10,330,999 [Application Number 14/717,059] was granted by the patent office on 2019-06-25 for display panel and method of manufacturing the same.
This patent grant is currently assigned to SAMSUNG DISPLAY CO., LTD.. The grantee listed for this patent is SAMSUNG DISPLAY CO., LTD.. Invention is credited to Jin-Ho Ju, Yang-Ho Jung, Hoon Kang, Chul-Won Park, Koichi Sugitani.
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United States Patent |
10,330,999 |
Sugitani , et al. |
June 25, 2019 |
Display panel and method of manufacturing the same
Abstract
A display panel includes a substrate, a thin-film transistor
(TFT) disposed on the substrate, a first electrode electrically
connected to the thin-film transistor, a roof layer disposed on the
first electrode and a liquid crystal layer. The roof layer includes
an organic insulating material, and defines a cavity that overlaps
the first electrode. The liquid crystal layer is disposed in the
cavity and is in direct contact with the roof layer.
Inventors: |
Sugitani; Koichi (Hwaseong-si,
KR), Kang; Hoon (Suwon-si, KR), Park;
Chul-Won (Gwangmyeong-si, KR), Jung; Yang-Ho
(Seoul, KR), Ju; Jin-Ho (Seoul, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG DISPLAY CO., LTD. |
Yongin, Gyeonggi-do |
N/A |
KR |
|
|
Assignee: |
SAMSUNG DISPLAY CO., LTD.
(Yongin, Gyeonggi-do, KR)
|
Family
ID: |
54151140 |
Appl.
No.: |
14/717,059 |
Filed: |
May 20, 2015 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20160085099 A1 |
Mar 24, 2016 |
|
Foreign Application Priority Data
|
|
|
|
|
Sep 22, 2014 [KR] |
|
|
10-2014-0125851 |
Mar 25, 2015 [KR] |
|
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10-2015-0041455 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
27/1214 (20130101); H01L 27/1288 (20130101); G02F
1/1368 (20130101); G02F 1/133377 (20130101); G02F
1/1337 (20130101); G02F 1/1341 (20130101); H01L
27/124 (20130101); G02F 1/133514 (20130101); G02F
1/133516 (20130101); G02F 1/134363 (20130101); G02F
2001/136222 (20130101) |
Current International
Class: |
G02F
1/1333 (20060101); H01L 27/12 (20060101); G02F
1/1343 (20060101); G02F 1/1362 (20060101); G02F
1/1368 (20060101); G02F 1/1337 (20060101); G02F
1/1335 (20060101); G02F 1/1341 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2008-242247 |
|
Oct 2008 |
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JP |
|
1020050031857 |
|
Apr 2005 |
|
KR |
|
1020130140325 |
|
Dec 2013 |
|
KR |
|
1020140056489 |
|
May 2014 |
|
KR |
|
Other References
Search Report dated Jan. 12, 2016 from the European Patent Office
in corresponding European Patent Application No. 15185822.2. cited
by applicant.
|
Primary Examiner: Gross; Alexander P
Attorney, Agent or Firm: F. Chau & Associates, LLC
Claims
What is claimed is:
1. A display panel comprising: a substrate; a thin-film transistor
(TFT) disposed on the substrate; a first electrode electrically
connected to the thin-film transistor; a roof layer positioned
above the first electrode and substantially consisting of an
organic insulating material to exclude an inorganic layer and
defining a cavity that overlaps the first electrode; and a liquid
crystal layer disposed in the cavity, wherein the roof layer is in
direct contact with an upper surface of the liquid crystal layer
facing away from the first electrode, and wherein a portion of the
roof layer extends continuously from a portion above the liquid
crystal layer to be in direct contact with a passivation layer
disposed on the first electrode.
2. The display panel of claim 1, wherein the cavity has a tunnel
shape.
3. The display panel of claim 1, wherein the roof layer is a color
filter.
4. The display panel of claim 1, further comprising a color filter
overlapping the first electrode.
5. The display panel of claim 1, further comprising a second
electrode overlapping the first electrode and receiving a common
voltage, wherein the first electrode or the second electrode
includes a plurality of slits.
6. The display panel of claim 1, wherein the roof layer includes a
negative photoresist composition comprising an acryl compound and a
photoinitiator.
7. A display panel comprising: a substrate; a thin-film transistor
(TFT) disposed on the substrate; a first electrode electrically
connected to the thin-film transistor; a roof layer positioned
above the first electrode and defining a cavity that overlaps the
first electrode; an alignment layer disposed in the cavity and
being in direct contact with the roof layer; and a liquid crystal
layer disposed in the cavity and being in direct contact with the
alignment layer, wherein the roof layer is in direct contact with
and covers an upper surface of the alignment layer facing way from
the liquid crystal layer, and wherein a portion of the roof layer
extends continuously from the upper surface of the alignment layer
to be in direct contact with a passivation layer disposed on the
first electrode.
8. The display panel of claim 7, wherein the roof layer is a color
filter.
9. The display panel of claim 7, further comprising a color filter
overlapping the first electrode.
10. A method of manufacturing a display panel, the method
comprising: forming a thin-film transistor (TFT) and a first
electrode electrically connected to the thin-film transistor on a
substrate; depositing a positive photoresist composition on the
first electrode to form a sacrificial layer; light-exposing and
developing the sacrificial layer to form a sacrificial pattern;
depositing a negative photoresist composition on the sacrificial
pattern to form a roof layer entirely covering the sacrificial
pattern; and removing the sacrificial pattern to form a cavity.
11. The method of claim 10, further comprising: forming a color
filter overlapping the first electrode and disposed under the color
filter.
12. The method of claim 10, further comprising: injecting a liquid
crystal into the cavity to form a liquid crystal layer.
13. The method of claim 10, wherein the cavity has a tunnel
shape.
14. The method of claim 13, wherein an amide stripper is provided
to the sacrificial pattern to remove the sacrificial pattern.
15. The method of claim 10, wherein the positive photoresist
composition comprises a polyamide compound, a photosensitive
quinone diazide compound and a first solvent.
16. The method of claim 15, wherein the first solvent comprises
propylene glycol monomethyl ether (PGME), cyclohexanone, ethyle
lactate (EL), .gamma.-butyrolactone (GBL) or N-methylpyrrolidione
(NMP).
17. The method of claim 15, wherein the negative photoresist
composition comprises an acryl compound, a photo initiator, a
coloring agent and a second solvent, and the roof layer is a color
filter partially covering the sacrificial pattern.
18. The method of claim 17, further comprising: forming a
protection layer covering the color filter.
19. The method of claim 15, wherein the negative photoresist
composition comprises an acryl compound, a photo initiator and a
second solvent.
20. The method of claim 19, wherein the polyamide compound is
insoluble in the second solvent, and the acryl compound is
insoluble in the first solvent.
21. The method of claim 19, wherein the second solvent comprises
propylene glycol methyl ether acetate (PGMEA).
Description
CROSS-REFERENCE TO RELATED APPLICATION
This U.S. non-provisional application claims priority under 35
U.S.C. .sctn. 119 to Korean Patent Application No. 10-2014-0125851,
filed on Sep. 22, 2014, and Korean Patent Application No.
10-2015-0041455, filed on Mar. 25, 2015, the disclosures of which
are incorporated by reference herein in their entireties.
TECHNICAL FIELD
Exemplary embodiments of the present invention relate to a display
panel and a method of manufacturing the same.
DISCUSSION OF RELATED ART
A display panel may include an array substrate, a color filter
substrate and a liquid crystal layer disposed between the array
substrate and the color filter substrate. The array substrate may
include switching elements, and the color filter substrate may have
color filters disposed thereon. The array substrate may include a
first base substrate and the color filter substrate may include a
second base substrate.
An embedded micro-cavity display panel may include switching
elements and color filters on a single base substrate.
When the embedded micro-cavity display panel is manufactured, a
sacrificial layer may be formed to form a tunnel-shaped cavity. The
sacrificial layer may be hard-baked to harden the sacrificial layer
and to remove gas included therein.
When a process temperature for hard-baking is increased, edges of
the sacrificial layer may be disposed higher than a middle of the
sacrificial layer due to thermal reflow. Thus, edges of the display
panel corresponding to the edges of the sacrificial layer may be
relatively dark and an aperture ratio may be decreased.
When layers are formed on the sacrificial layer without hard-baking
to prevent thermal reflow, wrinkles may occur on an upper surface
of the sacrificial layer. This may cause wrinkles on layers which
are formed on the sacrificial layer.
SUMMARY
Exemplary embodiments of the present invention provide a display
panel including a sacrificial layer and a roof layer including
phase separable materials, which may increase an aperture
ratio.
Exemplary embodiments of the present invention provide a method of
manufacturing the display panel.
In accordance with an exemplary embodiment of the present
invention, a display panel includes a substrate, a thin-film
transistor (TFT) disposed on the substrate, a first electrode
electrically connected to the thin-film transistor, a roof layer
disposed on the first electrode and a liquid crystal layer. The
roof layer includes an organic insulating material, and defines a
cavity that overlaps the first electrode. The liquid crystal layer
is disposed in the cavity and is in direct contact with the roof
layer.
In an exemplary embodiment of the present invention, the cavity may
have a tunnel shape.
In an exemplary embodiment of the present invention, the roof layer
may be a color filter.
In an exemplary embodiment of the present invention, the display
panel may further include a color filter overlapping the first
electrode.
In an exemplary embodiment of the present invention, the display
panel may further include a second electrode overlapping the first
electrode and receiving a common voltage. The first electrode or
the second electrode may include a plurality of slits.
In accordance with an exemplary embodiment of the present
invention, a display panel includes a substrate, a thin-film
transistor (TFT) disposed on the substrate, a first electrode
electrically connected to the thin-film transistor, a roof layer
disposed on the first electrode, an alignment layer and a liquid
crystal layer. The roof layer includes an organic insulating
material, and defines a cavity that overlaps the first electrode.
The alignment layer is disposed in the cavity and is in direct
contact with the roof layer. The liquid crystal layer is disposed
in the cavity and is in direct contact with the alignment
layer.
In accordance with an exemplary embodiment of the present
invention, a method of manufacturing a display panel includes
forming a thin-film transistor (TFT) and a first electrode
electrically connected to the thin-film transistor on a substrate.
A positive photoresist composition is deposited on the first
electrode to form a sacrificial layer. The sacrificial layer is
light-exposed and developed to form a sacrificial pattern. A
negative photoresist composition is deposited on the sacrificial
pattern to form a roof layer in direct contact with the sacrificial
pattern. The sacrificial pattern is removed.
In an exemplary embodiment of the present invention, the positive
photoresist composition may include a polyamide compound, a
photosensitive quinone diazide compound and a first solvent.
In an exemplary embodiment of the present invention, the negative
photoresist composition may include an acryl compound, a photo
initiator and a second solvent. The roof layer may entirely cover
the sacrificial pattern.
In an exemplary embodiment of the present invention, the polyamide
compound may be insoluble in the second solvent. The acryl compound
may be insoluble in the first solvent.
In an exemplary embodiment of the present invention, the first
solvent may include propylene glycol monomethyl ether (PGME),
cyclohexanone, ethyle lactate (EL), .gamma.-butyrolactone (GBL) or
N-methylpyrrolidione (NMP).
In an exemplary embodiment of the present invention, the second
solvent may include propylene glycol methyl ether acetate
(PGMEA).
In an exemplary embodiment of the present invention, the negative
photoresist composition may include an acryl compound, a photo
initiator, a coloring agent and a second solvent. The roof layer
may be a color filter partially covering the sacrificial
pattern.
In an exemplary embodiment of the present invention, a protection
layer may be further formed to cover the color filter.
In an exemplary embodiment of the present invention, a color filter
may be further formed under the first electrode
In an exemplary embodiment of the present invention, the tunnel may
have a tunnel shape.
In an exemplary embodiment of the present invention, an amide
stripper may be provided to the sacrificial pattern to remove the
sacrificial pattern.
In an exemplary embodiment of the present invention, a liquid
crystal may be injected into a space formed by removing the
sacrificial pattern to form a liquid crystal layer.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features of the present invention will become
more apparent by describing in detail exemplary embodiments thereof
with reference to the accompanying drawings, in which:
FIG. 1 is a plan view illustrating a display panel in accordance
with an exemplary embodiment of the present invention;
FIG. 2 is a plan view illustrating a first pixel of the display
panel in FIG. 1 in accordance with an exemplary embodiment of the
present invention;
FIG. 3 is a cross-sectional view taken along line I-I' in FIG. 1 in
accordance with an exemplary embodiment of the present
invention;
FIGS. 4A, 4B, 4C, 4D, 4E and 4F are cross-sectional views taken
along the line I-I' in FIG. 1 illustrating a method of
manufacturing a display panel in accordance with exemplary
embodiments of the present invention; and
FIG. 5 is a cross-sectional view taken along the line I-I' in FIG.
1 in accordance with an exemplary embodiment of the present
invention.
FIGS. 6A, 6C, 6E, 6G, 6I, 6K and 6L are cross-sectional views taken
along line I-I' in FIG. 1 and illustrating a method of
manufacturing a display panel in accordance with exemplary
embodiments of the present invention.
FIGS. 6B, 6D, 6F, 6H and 6J are plan views illustrating a method of
manufacturing a display panel in accordance with exemplary
embodiments of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Hereinafter, exemplary embodiments of the present invention will be
described in more detail with reference to the accompanying
drawings.
FIG. 1 is a plan view illustrating a display panel in accordance
with an exemplary embodiment of the present invention.
Referring to FIG. 1, a display panel may include a plurality of
gate lines GL, a plurality of data lines DL and a plurality of
pixels (e.g., pixels P1 and P2).
The gate lines GL may extend in a first direction D1. The data
lines DL may extend in a second direction substantially
perpendicular to the first direction D1. The gate lines GL may
extend in the second direction D2 and the data lines DL may extend
in the first direction D1.
The pixels may be disposed in a matrix shape. The pixels may be
respectively disposed in areas defined by the gate lines GL and the
data lines DL.
Each pixel may be connected to a corresponding gate line GL and a
corresponding data line DL adjacent to the pixel.
Each pixel may have a rectangular shape extending in the second
direction D2, a V-shape, or a Z-shape, for example.
FIG. 2 is a plan view illustrating a pixel of the display panel in
FIG. 1 in accordance with an exemplary embodiment of the present
invention. FIG. 3 is a cross-sectional view taken along line I-I'
in FIG. 1 in accordance with an exemplary embodiment of the present
invention.
Referring to FIGS. 1 to 3, the display panel may include a
substrate 100, thin film transistors TFT, a gate insulating layer
110, a data insulating layer 120, a black matrix BM, a color filter
130, a first electrode EL1, a passivation layer 140, a second
electrode EL2, a liquid crystal layer 150 and a roof layer 160.
The substrate 100 may be a transparent insulating substrate.
According to exemplary embodiments of the present invention, the
transparent insulating substrate may be, but is not limited to, a
glass substrate, or a plastic substrate.
The substrate 100 may include a plurality of pixel areas for
displaying an image. The plurality of the pixel areas may be
disposed in a matrix shape having a plurality of rows and a
plurality of columns.
Each pixel may include a switching element. For example, the
switching element may be the thin film transistor TFT. The
switching element may be connected to the gate line GL and the data
line DL adjacent to the switching element. The switching element
may be disposed at a crossing area of the gate line GL and the data
line DL.
A gate pattern may include a gate electrode GE and the gate line
GL. The gate pattern may be disposed on the substrate 100. The gate
line GL may be electrically connected to the gate electrode GE.
The gate insulating layer 110 may be disposed on the substrate 100
and may cover the gate pattern. The gate insulating layer 110 may
insulate the gate pattern.
A semiconductor pattern SM may be disposed on the gate insulating
layer 110. The semiconductor pattern SM may overlap the gate
electrode GE.
A data pattern may include the data line DL, a source electrode SE
and a drain electrode DE. The data pattern may be disposed on the
semiconductor pattern SM, which may be disposed on the gate
insulating layer 110. The source electrode SE may overlap the
semiconductor pattern SM. The source electrode SE may be
electrically connected to the data line DL.
The drain electrode DE may be spaced apart from the source
electrode SE on the semiconductor pattern SM. The semiconductor
pattern SM may have a conductive channel between the source
electrode SE and the drain electrode DE.
The thin film transistor TFT may include the gate electrode GE, the
source electrode SE, the drain electrode DE and the semiconductor
pattern SM.
The data insulating layer 120 may be disposed on the gate
insulating layer 110. The data insulating layer 120 may insulate
the data pattern.
The gate insulating layer 110 and the data insulating layer 120 may
include an organic insulating material or an inorganic insulating
material. For example, the gate insulating layer 110 and the data
insulating layer 120 may include silicon oxide (SiO.sub.X) and/or
silicon nitride (SiN.sub.X).
A plurality of color filters 130 and a plurality of black matrices
BM may be disposed on the data insulating layer 120.
The color filters 130 may be disposed between adjacent data lines
DL. The color of light may be changed by the color filters 130 and
the light may penetrate the liquid crystal layer 150.
Each color filter 130 may correspond to one of the pixel areas. For
example, the color filters 130 may include a red color filter,
green color filter and a blue color filter. The color filters 130,
which may be adjacent to each other, may have different colors from
each other. For example, the color filters 130 may be spaced apart
from a border between adjacent pixel areas.
The color filters 130 may be disposed in an island shape and may be
spaced apart from each other. Alternatively, the color filters 130
may be adjacent to each other and may partially overlap each other
at a border between adjacent pixel areas.
The display panel may include signal lines and black matrices BM.
The signal lines may be connected to the thin film transistor TFT.
The black matrices BM may overlap the signal lines and may block
light.
The black matrices BM may be disposed on a border between adjacent
pixel areas. For example, the black matrices BM may be disposed
between adjacent color filters 130.
The black matrices BM may be disposed on an area where the gate
line GL, the data line DL and the switching element are disposed.
For example, the black matrices BM may be disposed on a non-display
area.
For example, the black matrices BM may include a photosensitive
organic material including a pigment, such as carbon black.
The first electrode EL1 may be disposed on the color filter 130.
The first electrode EL1 may be disposed in the pixel area. The
first electrode EL1 may overlap the color filter 130. The first
electrode EL1 may be electrically connected to the thin film
transistor TFT. A grayscale voltage may be applied to the first
electrode EL1 through the thin film transistor TFT.
For example, the first electrode EL1 may include a transparent
conductive material, such as indium tin oxide (ITO), indium zinc
oxide (IZO) and/or aluminum zinc oxide (AZO). The first electrode
EL1 may have a continuous plate shape.
The passivation layer 140 may be disposed on the first electrode
EL1 and the black matrices BM. The passivation layer 140 may cover
the first electrode EL1 and the black matrices BM. The passivation
layer 140 may be formed on a whole surface of the substrate
100.
The passivation layer 140 may include an organic insulating
material or an inorganic insulating material. For example, the
passivation layer 140 may include silicon oxide (SiO.sub.X) and/or
silicon nitride (SiN.sub.X).
The second electrode EL2 may be disposed on the passivation layer
140. The passivation layer 140 may overlap the first electrode
EL1.
For example, the second electrode EL2 may include a transparent
conductive material such as indium tin oxide (ITO), aluminum zinc
oxide (AZO) and/or indium zinc oxide (IZO). For example, the second
electrode EL2 may have a slit pattern.
For example, a common voltage may be applied to the second
electrode EL2. Thus, the first electrode EL1 may function as a
pixel electrode, and the second electrode EL2 may function as a
common electrode. In another exemplary embodiment, the second
electrode EL2 may be electrically connected to the thin film
transistor TFT to receive the grayscale voltage, and the first
electrode EL1 may receive the common voltage. Furthermore, the
first electrode EL1 may have a slit pattern, and the second
electrode EL2 may have a continuous plate shape.
The liquid crystal layer 150 may be disposed on one or more of the
color filters 130 and may overlap one or more of the color filters
130.
The liquid crystal layers 150 may be disposed on adjacent pixel
areas, and the liquid crystal layers 150 may be spaced apart from
the data lines, which may be a border.
The liquid crystal layer 150 may include one or more liquid crystal
molecules. The liquid crystal molecules may be aligned by an
electric field applied between the first electrode EL1 and the
second electrode EL2. Therefore, a light transmittance of the pixel
may be controlled.
The roof layer 160 may be disposed on the liquid crystal layer 150.
The roof layer 160 may be in direct contact with the liquid crystal
layer 150.
The roof layer 160 may cover the liquid crystal layer 150. The roof
layer may include a wall 161 disposed between the liquid crystal
layers 150. For example, the wall 161 may overlap with the data
lines DL. The wall 161 may maintain a shape of the roof layer 160.
The roof layer 160 may include a plurality of walls.
The roof layer 160 may include an organic insulating material. For
example, the organic insulating material may include a material
capable of being hardened by exposure to light or heat. Thus, the
roof layer 160 may be hardened by exposure to heat or light.
A stripper injecting hole may be formed in the roof layer 160,
thereby exposing the liquid crystal layer 150. An encapsulating
layer may also be disposed on the roof layer 160. The encapsulating
layer may cover the stripper injecting hole and may prevent the
liquid crystal molecules from leaking.
FIGS. 4A, 4B, 4C, 4D, 4E and 4F are cross-sectional views taken
along the line I-I' in FIG. 1 illustrating a method of
manufacturing a display panel in accordance with exemplary
embodiments of the present invention.
Referring to FIGS. 1 to 4F, steps of manufacturing a display panel
in accordance with an exemplary embodiment of the present invention
are illustrated in more detail.
Referring to FIGS. 1 to 4C, the gate insulating layer 110, the data
line DL, the data insulating layer 120, the color filter 130, the
black matrix BM, the first electrode EL1 and the second electrode
EL2 may be formed on the substrate 100. A sacrificial layer SL may
be formed on the substrate 100.
The gate pattern including the gate electrode GE and the gate line
GL may be formed on the substrate 100. A first conductive layer may
be formed on the substrate 100 and may be patterned by a
photolithograph process, thus forming the gate pattern.
The gate insulating layer 110 may be formed on the substrate 100 to
cover the gate pattern. The gate insulating layer 110 may insulate
the gate pattern.
The semiconductor pattern SM may be formed on the gate insulating
layer 110. The semiconductor pattern SM may overlap the gate
electrode GE.
The data pattern including the data line DL, the source electrode
SE and the drain electrode DE may be formed on the gate insulating
layer 110 on which the semiconductor pattern SM may be formed. A
second conductive layer may be formed on the gate insulating layer
110 and may be patterned by a photolithography process, thus
forming the data pattern.
The drain electrode DE may be spaced apart from the source
electrode SE with respect to the semiconductor pattern SM. The
semiconductor pattern SM may have a conductive channel between the
source electrode SE and the drain electrode DE.
The thin film transistor TFT may include the gate electrode GE, the
source electrode SE, the drain electrode DE and the semiconductor
pattern SM.
The data insulating layer 120 may be formed on the gate insulating
layer 110 on which the data pattern may be formed.
The color filter 130 may be formed on the substrate 100 on which
the data line DL may be formed. The color filter 130 may be
disposed between adjacent data lines DL.
The black matrix BM may be formed on a border between adjacent
pixel areas. For example, the black matrix BM may be disposed
between adjacent color filter 130. The black matrix BM may be
disposed on an area where the gate line GL, the data line DL and
the switching element are disposed. For example, the black matrix
BM may include a photosensitive organic material including a
pigment, such as carbon black. For example, the display panel may
include a plurality of black matrices BM.
A positive photoresist composition may be deposited on the color
filter 130 and the black matrix BM, thus forming the sacrificial
layer SL.
The sacrificial layer SL may be partially removed, which may form a
space for forming a cavity. Accordingly, the sacrificial layer SL
may be formed at a position where the liquid crystal layer 150 is
formed. The sacrificial layer SL may determine a width and height
of the cavity.
The sacrificial layer SL may be formed by depositing the positive
photoresist composition.
The positive photoresist composition will be described in more
detail below with respect to a negative photoresist
composition.
For example, the sacrificial layer SL may be formed by an inkjet
process, or a spin-coating process.
The sacrificial layer SL may be soft-baked prior to being exposed
to light. For example, the sacrificial layer SL may be soft-baked
within a temperature range of about 120.degree. C. to about
130.degree. C.
The mask MASK may include a transparent part T and a blocking part
B. The mask MASK may be disposed above the substrate 100. The
transparent part T may allow light to pass through it to the data
line DL and the black matrix BM. The blocking part B may block
light emitted toward the color filter 130. The sacrificial layer SL
may be exposed to light using the mask MASK.
An exposed portion of the sacrificial layer SL may be partially
removed by using a developer, thus forming a sacrificial pattern
SL'.
The developer may include an alkali solution. For example, the
developer may be an amide solution.
Referring to FIG. 4D, the negative photoresist composition may be
deposited on the sacrificial patter SL' thus forming a roof layer
160.
The roof layer 160 may be formed on the sacrificial pattern SL'.
The roof layer 160 may be in direct contact with the sacrificial
pattern SL'. The roof layer 160 may entirely cover the sacrificial
pattern SL'.
Phases of the sacrificial pattern SL' and the roof layer 160 may be
separated from each other. The roof layer 160 may include the
negative photoresist composition and the sacrificial pattern SL'
may include the positive photoresist composition, thus the roof
layer 160 and the sacrificial pattern SL' may not be mixed so that
a separation between the roof layer 160 and the sacrificial pattern
SL' may be maintained.
For example, the positive photoresist composition may include a
polyamide compound, a photosensitive quinone diazide compound and a
first solvent.
For example, the polyamide compound may include polyamic acid,
which is a precursor of polyimide. Polyamic acid may be cured to
form a polyimide resin. For example, the polyamide compound may
include a repeating unit represented by the following Chemical
Formula 1.
##STR00001##
R1 and R2 may be respectively an alkyl group (alkylene group)
having 1 to 20 carbon atoms or an aromatic group, R3 and R4 may be
respectively an alkyl group having 1 to 20 carbon atoms, an
aromatic group or
##STR00002## R5 may be a hydrogen atom, a hydroxyl group, an alkyl
group having 1 to 20 carbon atoms or an aromatic group.
The polyamide compound may be formed by a condensation reaction
between a diamine compound and dianhydride compound.
Thus, R2 may be derived from the diamine compound. For example, the
diamine compound may be 3,4'-diaminodiphenylether,
4,4'-diaminodiphenylether, 3,4'-diaminodiphenylmethane,
4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone,
4,4'-diaminodiphenylsulfide, benzidine, m-phenylenediamine,
p-phenylenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine,
bis(4-aminophenoxyphenyl)sulfone, bis(3-aminophenoxyphenyl)sulfone,
bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, or
1,4-bis(4-aminophenoxy)benzene.
A weight-average molecular weight of the polyamide compound may be
in a range of about 3,000 to about 300,000. The polyamide compound
having this range of weight-average molecular weight may have
relatively high solubility in the first solvent.
The photosensitive quinone diazide compound may include
naphthoquinone diazide or benzoquinone diazide.
The polyamide compound may be soluble in the first solvent.
For example, the first solvent may include propylene glycol
monomethyl ether (PGME), cyclohexanone, ethyle lactate (EL),
.gamma.-butyrolactone (GBL) and/or N-methylpyrrolidione (NMP).
For example, based on a total weight of the positive photoresist
composition, the positive photoresist composition may include about
5 wt % to about 70 wt % of the polyamide compound, about 0.5 wt %
to about 30 wt/o of the photosensitive quinone diazide compound and
a remainder of the first solvent.
The negative photoresist composition may include an acryl compound,
a photo initiator and a second solvent.
For example, the acryl compound may be polyacrylate resin, or poly
methacrylate resin.
For example, the photo initiator may be a halogen-containing
iminosulfonate photo initiator including a halogen, a
diazonaphthoquinone-4-sulfonate photo acid generator, or a triazine
photo initiator.
The acryl compound may be soluble in the second solvent.
For example, the second solvent may include propylene glycol methyl
ether acetate (PGMEA).
For example, the polyamide compound may be insoluble in the second
solvent.
The second solvent does not include a functional group capable of
hydrogen bonding so that the polyamide compound having a polarity
may be relatively insoluble in the second solvent.
For example, based on a total weight of the negative photoresist
composition, the negative photoresist composition may include about
5 wt % to about 70 wt % of the acryl compound, about 1 wt % to
about 35 wt % of the photo initiator and a remainder of the second
solvent.
Thus, when the negative photoresist composition is deposited on the
sacrificial pattern SL', the sacrificial pattern SL' and the
negative photoresist composition are not mixed, thus separating
phases thereof and maintaining a shape of the roof layer 160.
Referring to FIGS. 1 to 4E, after forming the roof layer 160, the
sacrificial pattern SL' may be removed using a stripper.
Prior to removing the sacrificial pattern SL' using the stripper, a
stripper injection hole may be formed. Furthermore, the substrate
including the sacrificial pattern SL' may be entirely exposed to a
light to increase a solubility of the sacrificial pattern SL'
before the stripper is provided.
The stripper may be injected into the sacrificial pattern SL'
through the stripper injection hole. Thus, a cavity 145 may be
formed in a position where the sacrificial pattern SL' was formed.
The cavity 145 may have a tunnel shape extending in a direction.
For example, the cavity 145 may extend in a direction substantially
parallel to the data line DL. The cavity 145 may overlap at least
one of the first electrode EL1 and the second electrode EL2.
The stripper may include an alkali solution. For example, the
stripper may be an amide solution. The stripper including the amide
solution may entirely remove the sacrificial pattern SL', however a
structure of the roof layer 160 may be maintained.
The removal of the sacrificial pattern SL' by the developer may be
performed at about 23.degree. C. to about 26.degree. C. The removal
of the sacrificial pattern SL' may be accelerated by increasing the
processing temperature. For example, the sacrificial pattern SL'
may be removed by the developer at about 23.degree. C. to about
80.degree. C.
Referring to FIGS. 1 to 4F, liquid crystal may be injected into the
cavity 145, thus forming the liquid crystal layer 150.
The liquid crystal may be in the form of a fluid. The liquid
crystal may flow into the cavity 145 by capillary action. For
example, the liquid crystal may be provided into the cavity 145
through the stripper injecting hole.
The liquid crystal may be provided into the cavity 145 by using an
inkjet having a micropipette. Alternatively, the liquid crystal may
be provided into the cavity 145 by using a vacuum injection
apparatus.
An encapsulating layer may be disposed on the roof layer 160 so
that the encapsulating layer may cover the stripper injecting hole
to prevent the liquid crystal from leaking.
FIG. 5 is a cross-sectional view taken along the line I-I' in FIG.
1 in accordance with an exemplary embodiment of the present
invention.
Referring to FIG. 5, the display panel may include the substrate
100, thin film transistors TFT, the gate insulating layer 110, the
data insulating layer 120, the black matrix BM, the color filter
130, the first electrode EL1, the passivation layer 140, the second
electrode EL2, the lower alignment layer AL1, the liquid crystal
layer 150, the upper alignment layer AL2 and the roof layer
160.
The display panel illustrated in FIG. 5 may be substantially the
same as that of the display panel illustrated in FIG. 3 except for
the lower alignment layer AL1 and the upper alignment layer AL2,
and thus repetitive explanations concerning the above elements may
be omitted.
The lower alignment layer AL1 may be disposed on the color filters
130. For example, the lower alignment layer AL1 may be disposed
between the passivation layer 140 and the second electrode EL2.
The liquid crystal layer 150 may be disposed on the lower alignment
layer AL1. The liquid crystal layer 150 may overlap the color
filters 130.
The upper alignment layer AL2 may be disposed on the liquid crystal
layer 150.
The roof layer 160 may be in direct contact with the upper
alignment layer AL2, thus covering the upper alignment layer AL2.
For example, the roof layer 160 may include an organic insulating
material.
The lower alignment layer AL1 and the upper alignment layer AL2 may
pretilt the liquid crystal molecules of the liquid crystal layer
150.
For example, the lower alignment layer AL1 and the upper alignment
layer AL2 may have a thickness of about 10 .mu.m to about 100
.mu.m.
The lower alignment layer AL1 and the upper alignment layer AL2 may
include an aligning composition.
The liquid crystal layer 150 may be exposed through the roof layer
160 by forming a stripper injection hole.
The aligning composition may be deposited in the cavity 145 through
the stripper injection hole, and then the aligning composition may
be dried to remove a solvent thereof. For example, the aligning
composition may be dried at room temperature or may be heated.
While the sacrificial pattern SL' and the roof layer 160 are formed
on the color filter 130 in the above exemplary embodiment, a color
filter may function as a roof layer in another exemplary
embodiment.
FIGS. 6A, 6C, 6E, 6G, 6I, 6K and 6L are cross-sectional views taken
along line I-I' in FIG. 1 and illustrating a method of
manufacturing a display panel in accordance with exemplary
embodiments of the present invention. FIGS. 6B, 6D, 6F and 6J are
plan views illustrating a method of manufacturing a display panel
in accordance with exemplary embodiments of the present invention.
Particularly, FIG. 6B is a plan view of FIG. 6A. FIG. 6D is a plan
view of FIG. 6C. FIG. 6F is a plan view of FIG. 6E. FIG. 6H is a
plan view of FIG. 6G. FIG. 6J is a plan view of FIG. 6I.
A configuration of a thin film transistor of the display panel may
be explained with reference to FIG. 2. The display panel may be
substantially the same as the display panel illustrated in FIGS. 1,
2, and 5 except for including a color filter functioning as a roof
layer. Thus, any duplicated explanation may be omitted.
Referring to FIGS. 2, 6A and 6B, a gate pattern, a gate insulation
layer 210, a semiconductor pattern SM, a data pattern, a data
insulation layer 220, a first electrode EL1, a passivation layer
230, a second electrode EL2 and a black matrix BM are formed on a
substrate 200.
The gate pattern may include a gate line GL and a gate electrode GE
connected to the gate line GL.
The gate insulation layer 210 may cover the gate pattern.
The semiconductor pattern SM may be formed on the gate insulation
layer 210. The semiconductor pattern SM overlaps the gate electrode
GE.
The data pattern may include a source electrode SE, a drain
electrode DE and a data line DL. The source electrode SE and the
drain electrode DE contact the semiconductor pattern SM, and are
spaced apart from each other. The data line GL is connected to the
source electrode SE.
The data insulation layer 220 may cover the data pattern.
The first electrode EL1 may be formed on the data insulation layer
220. The passivation layer 230 may cover the first electrode
EL1.
The second electrode EL2 may be formed on the passivation layer
230. The second electrode EL2 includes a plurality of slits SP. For
example, the slits SP may extend in a direction substantially
parallel to the data line DL.
The black matrix BM may overlap the gate line GL. The black matrix
BM may have a linear shape extending a direction substantially
parallel to the gate line GL. The black matrix BM may be formed on
the passivation layer 230. In another exemplary embodiment, the
black matrix BM may be formed on the data insulation layer 220 to
be disposed between the data insulation layer 220 and the
passivation layer 230. In another exemplary embodiment, the black
matrix BM may be omitted.
Referring to FIGS. 6C and 6D, a sacrificial pattern SL' may be
formed on the second electrode EL2. The sacrificial pattern SL' may
entirely cover the second electrode EL2. The sacrificial pattern
SL' may further cover the black matrix BM. The sacrificial pattern
SL' may be formed through a substantially same method as the
sacrificial pattern SL' illustrated in FIG. 4C.
Referring to FIGS. 6E and 6F, a first color filter CF1 may be
formed on a first sacrificial pattern SL'. For example, a
photoresist composition may be coated on the first sacrificial
pattern SL', and exposed to a light and developed to form the first
color filter CF1. The photoresist composition may be a negative
photoresist composition. The photoresist composition may include an
acryl compound, a photo initiator, a coloring agent and a
solvent.
Examples of the acryl compound may include polyacrylate resin or
poly methacrylate resin. Examples of the photo initiator may
include a halogen-containing iminosulfonate photo initiator, a
diazonaphthoquinone-4-sulfonate photo acid generator, or a triazine
photo initiator. The solvent may include propylene glycol methyl
ether acetate (PGMEA).
For example, the photoresist composition may include about 5 wt %
to about 70 wt % of the acryl compound, about 1 wt % to about 35 wt
% of the photo initiator, about 1 wt % to about 30 wt % of the
coloring agent and a remainder of the solvent.
The sacrificial pattern SL' may include a positive photoresist
composition. Thus, the sacrificial pattern SL' may not be mixed
with the negative photoresist composition for forming a color
filter so that a separation between the sacrificial pattern SL' and
the color filter may be maintained.
The first color filter CF1 has a specific color, and is formed in
certain pixels of the entire pixels. For example, the first color
filter CF1 may include a red coloring agent. The photoresist
composition may include the red coloring agent such as a red
pigment to form a red color filter.
Referring to FIGS. 6G and 6H, a second color filter CF2 may be
formed on a second sacrificial pattern SL'. The second color filter
CF2 may be adjacent to the first color filter CF1, and may
partially overlap the first color filter CF1. The second color
filter CF2 may include a coloring agent different from the first
color filter CF1, for example, a green coloring agent. A
photoresist composition including a green pigment may be used for
forming a green color filter.
Even if not illustrated, at least one color filter having a
different color from the first color filter CF1 and the second
color filter CF2 may be further formed through a substantially same
method as the first color filter CF1 and the second color filter
CF2. For example, a third color filter may be a blue filter. A
fourth color filter may be a white filter, a yellow filter, a cyan
filter or a magenta filter.
The color filters overlap the second electrode EL2. Thus, a portion
of the sacrificial pattern SL' may be uncovered by the color
filters and exposed.
Referring to FIGS. 6I and 6J, the sacrificial pattern SL' may be
removed. A stripper is provided to remove the sacrificial pattern
SL'. Furthermore, the substrate including the sacrificial pattern
SL' may be entirely exposed to a light to increase a solubility of
the sacrificial pattern SL' before the stripper is provided.
A portion of the sacrificial pattern SL' is uncovered by the color
filters. Thus, the sacrificial pattern SL' may easily contact the
stripper. When the sacrificial pattern SL' is removed, a cavity 245
may be formed in a position where the sacrificial pattern SL' was
formed. The cavity 245 may have a tunnel shape extending in a
direction. For example, the cavity 245 may extend in a direction
substantially parallel to the data line DL. A plurality of cavities
245 may be spaced apart from each other in a direction parallel to
the gate line GL. In a plan view, the data line DL may be disposed
between adjacent cavities 245.
The stripper may include an alkali solution. For example, the
stripper may be an amide solution. The stripper including the amide
solution may entirely remove the sacrificial pattern SL' including
the polyamide compound without damaging a structure of the color
filters.
Referring to FIG. 6K, an alignment layer is formed in the cavity
245. An aligning composition may be provided in the cavity 245 to
form the alignment layer.
The alignment layer may include a lower alignment layer AL1
covering the second electrode EL2, and an upper alignment layer AL2
covering a lower surface of the color filter. While the lower
alignment layer AL1 and the upper alignment layer AL2 are
illustrated to be spaced apart from each other, the lower alignment
layer AL1 and the upper alignment layer AL2 may be substantially
connected to each other.
After the alignment layer is formed, a liquid crystal material may
be provided in the cavity 245 to form a liquid crystal layer. Thus,
the alignment layer may be in direct contact with the liquid
crystal layer. If the alignment layer is omitted in another
exemplary embodiment, the color filter may be in direct contact
with the liquid crystal layer.
Referring to FIG. 6L, a protection layer 250 may be formed to cover
the color filter. The protection layer 250 may protect the color
filter, and may include an organic material or an inorganic
material. Furthermore, the protection layer 250 may have a
single-layered structure or a multiple-layered structure including
an organic material layer and an inorganic material layer.
The display panel and the method for manufacturing the display
panel according to exemplary embodiments of the present invention
may be used for a liquid crystal display panel including one base
substrate and a liquid crystal display apparatus having the
same.
In accordance with exemplary embodiments of the present invention,
a sacrificial layer and a roof layer may formed in phase separable
materials so that the roof layer may be directly formed on an upper
surface of the sacrificial layer without forming an inorganic layer
on the sacrificial layer, thus reducing the number of masks.
Therefore, a hard-baking process of the sacrificial layer may be
skipped so that an aperture ratio is increased.
While the present invention has been particularly shown and
described with reference to exemplary embodiments thereof, it will
be understood by those of ordinary skill in the art that various
changes in form and detail may be made therein without departing
from the spirit and scope of the present invention as defined by
the following claims.
* * * * *